Fast Tool for Buckling Analysis and Optimization of Stiffened Panels

摘要

This paper presents a fast tool that can be used during the preliminary design of isotropic and composite stiffened panels subjected to axial compression. It consists of two modules, one for the analysis and one for the optimization. The analysis is performed by implementing an analytical formulation to obtain the linearized buckling load and to study the nonlinear postbuckling field. In particular, closed-form solutions are derived for the linearized local and global buckling loads, and a semi-analytical procedure is implemented for the study of the nonlinear local postbuckling field. The optimization is based on genetic algorithms and allows taking into account buckling and postbuckling requirements with reduced computational time. Two examples regarding the minimum weight optimization of an isotropic panel and a composite panel are discussed and verified by means of finite element eigenvalue and nonlinear analyses. The total time required for the analysis and the optimization is of the order of a few minutes, and the difference between the analytical and numerical results is below 9% for the buckling load and below 3% for the postbuckling stiffness.